Question

Resolva os sistemas abaixo:

a)2x-3y+5z=9
5y-z+3t=1
7z-t=3
2t=8


b)x+2y+z=12
y-z=6
2z=4

Answer 1

Resposta:

A)

2t=8

t = 8/2 → t = 4

7z - t = 3

7z - 4 = 3  →  7z = 3 + 4

7z = 7  →  z = 7/7  → z = 1

5y - z + 3t = 1  

5y - 1 + 3 . 4 = 1 → 5y - 1 + 12 = 1 → 5y = 1 + 1 - 12

5y = -10  →  y = -10/5   →   y = -5

2x-3y+5z=9

2x - 3 . (-5) + 5 . 1 = 9  → 2x + 15 +5 = 9  → 2x = 9 - 20

2x = -11 →  x = -11/2

B)

2z = 4

z = 4/2    →   z = 2

y - z = 6  

y - 2 = 6  →  y = 6 + 2  →  y = 8

x + 2y + z = 12

x + 2 . 8 + 2 = 12 →   x = 12 + 12  →  x = 24